Only nine states have 80-mph limits, but one will let drivers go 85 mph in certain areas.
North Dakota passed a new law raising its maximum speed limit on certain highways to 80 miles per hour. It goes into effect on August 1, 2025, and covers most sections of Interstate 94 and Interstate 29—the only major highways in the state. Its wide-open plains, straight highways, and light traffic are conducive to higher speeds without undue safety risks, something North Dakota’s neighbors learned years ago.
North Dakota is the ninth US state to adopt a speed limit of at least 80 mph. Most are located in America’s Great Plains, where space is vast and traffic is light. If you step further west, you can also find higher speed limits where fields and mountains give way to deserts.
These speeds are exclusive to limited-access interstate highways but usually drop around larger cities or in congested areas. For example, I-90 through South Dakota is 80 mph except at Sioux Falls on the east side, and for a 50-mile stretch on the west side from Rapid City to the Wyoming border, where motorcycle traffic is often heavier. Semi-trucks often have lower speed limits as well.
Whether you’re planning a road trip or merely curious about legal speed limits, here’s a current list of all the US states with maximum speed limits of at least 80 mph.
Idaho: 80 MPH (Cars) / 70 MPH (Semi-Trucks)
On rural stretches of Interstates 15, 84, and 86 in Idaho, the legal speed limit is 80 miles per hour for passenger cars and 70 miles per hour for semi-trucks. I-84 between Boise and Caldwell remains at 65 mph for all vehicles. Idaho raised its speed limits to 80 mph on July 1, 2014.
Montana: 80 MPH (Cars) / 70 MPH (Semi-Trucks)
Along Interstates 15, 90, and 94 in Montana, the posted speed limit is 80 miles per hour for passenger vehicles and 70 miles per hour for semi-trucks. Montana introduced the new speed limits on October 1, 2015, raising them from 75 mph.
Nevada: 80 MPH
The legal speed limit along a 30-mile stretch of Interstate 80 in Nevada between Fernley and Winnemucca (not including a section through Lovelock) is 80 miles per hour for all vehicles. Nevada increased the speed limit to 80 mph on May 8, 2017.
North Dakota: 80 MPH
The speed limit on Interstates 29 and 94 in North Dakota is 80 miles per hour for all vehicles. North Dakota is the latest state to raise its speed limits to 80 mph, doing so on May 5, 2025.
Oklahoma: 80 MPH
In Oklahoma, the 59-mile stretch of Interstate 44 / HE Baily Turnpike between Chickasha and Lawton has a posted speed limit of 80 miles per hour. Governor Kevin Stitt signed the bill into law in April 2019, raising the speed limit from 75 mph.
South Dakota: 80 MPH
Most rural Interstates in South Dakota have a posted speed limit of 80 miles per hour, with exceptions for urban areas near Sioux Falls, Rapid City, and North Sioux City. South Dakota raised its speed limits from 75 mph to 80 mph on April 1, 2015.
Utah: 80 MPH
On certain sections of Interstates 80, 15, and 84, the posted speed limit is 80 miles per hour, with exclusions for two mountain passes and Cedar City, where the speed limit drops to 75 miles per hour. Utah was the first US state to introduce 80 mph speed limits, doing so in January 2009.
Wyoming: 80 MPH
In Wyoming, rural Interstates 25, 80, and 90 have posted speed limits of 80 miles per hour. The state increased its speed limits on July 1, 2014.
Texas: 85 MPH
Texas has the highest posted speed limits of any state in the US. The 41-mile stretch of Texas State Highway 130 between SH 45 near Austin and Interstate 10 in Seguin has a posted speed limit of 85 miles per hour. It’s also known as the “Pickle Parkway.” The increased speed limits were approved in September 2012, with the parkway officially opened in October 2012.
CREDIT: Motor1.com Christopher Smith